The number of pieces of popcorn in a large movie theatre popcorn bucket is normally distributed, with a mean of 1515 and a standard deviation of 15. Approximately what percentage of buckets contain between 1470 and 1560 pieces of popcorn?
Approximately 68%
Approximately 75%
Approximately 95%
99.7%
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The answer is D) 99.7%
The empirical rule states that 99.7% of the data values will fall within 3 standard deviations of the mean. To calculate "within 3 standard deviations," you need to subtract 3 standard deviations from the mean, then add 3 standard deviations to the mean. That will give you the range for 99.7% of the data values.
1515 − 3 ⋅ 15 = 1470
1515 + 3 ⋅ 15 = 1560
The range of numbers is 1470 to 1560
Found using:
Empirical Rule Calculator with Easy Step-by-Step Solution
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